TubeNet

Has anyone any experience using a db meter to help with dynamics? If so would you recommend one that could be used in conjunction with tuba practice.

The standard SPL (sound pressure level) meter in use is the Radio Shack model. It measures the amount of sound present in dB. I think they cost about $50.00 or less. It's been a while since I bought mine. They can be used in many applications including setting up your home theater system. Although I've never used mine for practice with my horn I don't see why it wouldn't do a good job.
Good Luck, Phil

That Radio Shack one works great. The only caveat is that you need the one with the analog meter -- to give you a visual response.

It's useful to use in tandem with a tuner (preferably one with a similar analog meter) set the two side by side and practice crescendos / decrescendos with only moving the volume meter and trying not to move the tuner.

The audio meter is also good to discover how much louder one octave of a same note is than another... and to work on getting things as even as possible.
...a tool for visual feedback of an audial idea.

Can you give us a number for the Radio Shack one, or would it be the only one that they would have in stock?

33-250, Analog Display Sound Level Meter. The model number may have changed since I bought mine. Have a blast!